Tower supplying device and image forming apparatus using same toner supplying device

ABSTRACT

A toner supplying device for supplying toner contained in a toner container attached to the toner supplying device to a developing device of an image forming apparatus. The toner supplying device includes a toner container insertion part configured such that a toner container is inserted therein from a front side of the toner supplying device. A toner container holder that detachably holds the toner container inserted into the toner container insertion part and toner discharged from the toner container held by the toner container holder is exhausted to a toner exhaust path. A toner delivery device delivers the toner, exhausted to the toner exhaust path, to the developing device of the image forming apparatus, by mixing the toner with air. The toner supplying device includes a covering device that covers and uncovers the toner container insertion part. The covering device includes a regulating device that regulates movement of the covering device to cover and uncover the toner container insertion part. The regulating device regulates movement of the covering device to cover and uncover the toner container insertion part when toner is being discharged from the toner container held by the toner container holder in the toner insertion part and releases regulating movement of the covering device when toner is not being discharged from the toner container held by the toner container holder in the corresponding toner container insertion part.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a toner supplying device included in an imageforming apparatus.

2. Discussion of the Background

In image forming apparatuses using electrophotography, such as copyingapparatuses, facsimile apparatuses and printers, a latent image of imageinformation is formed on a surface of a drum or belt-like shaped imagebearing member by first uniformly charging the surface of the imagebearing member and then exposing the charged surface with lightmodulated with the image information. The latent image is then developedby toner, and the developed toner image is transferred onto a recordingmedium, such as a sheet of paper directly or via an intermediatetransfer member, thereby forming an image on the sheet of paper. Theimage forming apparatuses of this type include a developing device fordeveloping the latent image by toner, and generally include a tonersupplying device for supplying toner to the developing device as thedeveloping device consumes the toner as a result of developing images.

A toner container containing toner is attached to the toner supplyingdevice. Once the toner contained in the toner is consumed from beingsupplied to the developing device, the image forming apparatus generallystops the image forming operation and displays a message indicating thatthe toner container has run out of toner. The apparatus returns to anoperable state once the toner container is replaced with a new tonercontainer containing toner and the toner is supplied to the developingdevice.

As related art, Japanese Patent Laid Open Publication No. 2-277083describes a toner supplying device having a plurality of tonercontainers, which are disposed near a developing device. The tonercontainer chosen to supply toner to the developing device is changed byrotating the toner supplying device.

Japanese Patent Laid Open Publication No. 7-219329 describes a tonersupplying device placed apart and connected to a developing device via atoner delivery device which delivers toner while mixing the toner withair.

Japanese Patent Laid Open Publications No. 4-80779 and No. 8-137227describe a toner supplying device including a toner containeraccommodating device in which a plurality of toner containers can beattached. Toner discharged from each of the plurality of tonercontainers is merged with each other and conveyed to the developingdevice. Each of the plurality of toner containers is individuallyattachable to and detachable from the toner supplying device. The sizeof the toner container is made so that the container is easy to handle,and can be replaced with a new toner container without stopping theoperation of the apparatus.

Japanese Patent Laid Open Publication No. 8-137227 further describesthat the toner container accommodating device accommodates two tonercontainers. In addition, when a sensor detects non-existence of toner ina toner conveying pipe to a developing device, an agitator of one of thetwo toner containers, which has not been operated, begins to rotate tosupply toner therefrom.

The Japanese Patent Laid Open Publication No. 4-80779 further describesa sensor to detect a toner container which is set in the toner supplyingdevice, a detect device to detect non-existence of toner in the tonercontainer, and a display device to display an indication to indicatethat toner does not exist in the toner container of which thenon-existence of toner is detected. In addition, the Japanese PatentLaid Open Publication No. 4-80779 describes that the toner container,which has first been set to the toner supplying device, is first set tostart supplying toner to the developing device.

The Japanese Patent Laid Open Publication No. 8-137227 further describesthat when a toner container is set to a toner container holder, a tonerexit opening provided on an outer circumferential surface of the tonercontainer is opened. Toner contained in the toner container isdischarged from the toner exit opening by rotating an agitator providedinside the toner container. The agitator is rotated by an external drivedevice provided at a side of the toner container.

Also, Japanese Patent Laid Open Publication No. 7-5759 describes a tonercontainer which includes an opening at one end to discharge toner. Theopening is opened and closed by attaching and detaching a cap to theopening. The operation of attaching and detaching the cap is linked withan operation of an operator to replace the toner container, such thatthe operability of opening and closing the opening of the tonercontainer with the cap is facilitated.

A toner supplying device including a plurality of toner containers, asdescribed above in the background publications, has a problem in thatthe operability of attaching and detaching a toner container to and fromthe toner supplying device is poor. Further, rotating parts of the tonersupplying device, which are exposed, may incur danger of hurting anoperator when the operator attaches and detaches a toner container toand from the toner supplying device. Furthermore, toner scatters when atoner container is inserted into the toner supplying device through aninsertion inlet for the toner container.

In addition, the toner supplying device including a plurality of tonercontainers, as described above in the background publications, hasanother problem in that, if an operator sets an empty toner container(i.e., a toner container containing no toner), the set empty tonercontainer is not detected to be empty until an operating toner containerbecomes empty and the set empty toner container starts to be operated.This causes an intermittent supply of toner to a developing device, andthereby causes a decrease in the density of the toner in the developingdevice. Consequently, the resulting image quality is deteriorated.Stoppage of the image forming operation may also be caused.

Furthermore, the toner supplying device including a plurality of tonercontainers, as described in the above background publications, has yetanother problem in that an operator cannot easily recognize both thenon-existence of toner in each toner container and the nonexistence of atoner container itself in the toner supplying device. In addition,recognizing the remaining amount of toner in each of the tonercontainers is not easy. This causes a delay in replacing an empty tonercontainer, which is erroneously set or a toner container whose toner isused up, and thereby causes a delay in supplying toner to the developingdevice. Consequently, toner is intermittently supplied to the developingdevice. Further, if an operator replaces a toner container whose toneris not completely used up without knowing that some toner remains in thetoner container, toner may be scattered when the toner container isreplaced. Thus, toner may be unnecessarily wasted.

In addition, toner supplying device in which a plurality of tonercontainers, as described above in the background publications, has stillanother problem because the operation of opening and closing a tonerexit opening of a toner container with a cap is linked with theoperation of replacing the toner container and moving the tonercontainer to a position to start supplying toner therefrom. Therefore,if the toner container is replaced when the toner container ispositioned at an interim position between the position where the tonercontainer is replaced and the position where the toner container startsto supply toner therefrom, the cap is closed insufficiently, and thusthe cap may fall inside a toner container accommodating unit,subsequently hindering the operation of replacing the toner container,or toner may scatter and stain the inside of the toner supplying device.

In addition, an image forming apparatus including a toner supplyingdevice having a plurality of toner containers, as described above in thebackground art, has another problem in that attachment of the tonersupplying device to the main body of the image forming apparatus at anassembling line, when the apparatus is installed at a user's place foruse, or when the apparatus is overhauled is too complicated.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-discussedproblems and an object of the invention is to address and resolve theseand other problems. A non-exhaustive description of the features andattributes of the invention is presented in this section, with a morecomplete description provided by the figures and description of thepreferred embodiment section of this document.

A feature of the present invention is a novel toner supplying device forsupplying toner to a developing device of an image forming apparatus, inwhich the operability of attaching and detaching a toner container toand from the toner supplying device is improved with a simpleconfiguration, and scattering of toner and danger of hurting an operatorare prevented when an operator attaches and detaches a toner containerto and from the toner supplying device.

The present invention further provides a novel toner supplying devicethat prevents stoppage of toner supply to a developing device andthereby prevents a decrease of the density of toner in the developingdevice. Consequently, deterioration of the resulting image quality isprevented, even when an empty toner container is set to the tonersupplying device when one of a plurality of toner containers isreplaced. The novel toner supplying device further prevents stoppage ofthe image forming operation due to stoppage of toner supply to thedeveloping device, even when an empty toner container is set to thetoner supplying device.

Furthermore, the present invention provides a novel toner supplyingdevice in which the remaining amount of toner in a toner container setin the toner supplying device can be easily recognized via appropriateindications, and the operability of attaching and detaching a tonercontainer for replacement is improved. Thereby scattering of toner whena toner container is replaced, an intermittent toner supply to thedeveloping device and stoppage of the image forming operation areprevented.

Still furthermore, the present invention provides a novel tonersupplying device in which the operability of opening and closing a tonerexit opening of a toner container with a cap is improved, such that theopening is securely opened and closed by the cap. Thereby, the cap isprevented from falling off; the toner is not scattered, the inside ofthe toner supplying device is not stained, and the toner is notunnecessarily consumed.

The present invention further provides a novel image forming apparatusin which a toner supplying device can be attached to the main body ofthe apparatus in a safe and easy manner when the apparatus is assembledat an assembling line or when the apparatus is installed or overhauledat a user's location.

The above described, as well as may other attributes and features, areoffered by a novel toner supplying device for supplying toner, containedin each of a plurality of toner containers attached to the tonersupplying device, to a developing device of an image forming apparatus,according to the present invention. The toner supplying device includesa toner container insertion part that is configured such that a tonercontainer is inserted therein from a front side of the toner supplyingdevice. A toner container holder detachably holds the toner containerinserted into the toner container insertion part and toner dischargedfrom the toner container held by the toner container holder is exhaustedto a toner exhaust path. A toner delivery device delivers the toner,exhausted to the toner exhaust path, to the developing device of theimage forming apparatus, by mixing the toner with air. The tonersupplying device of the present invention includes a covering devicethat covers and uncovers the toner container insertion part. Thecovering device includes a regulating device that regulates movement ofthe covering device to cover and uncover the toner container insertionpart. The regulating device regulates movement of the covering device tocover and uncover the toner container insertion part when toner is beingdischarged from the toner container held by the toner container holderin the toner insertion part and releases regulating movement of thecovering device when toner is not being discharged from the tonercontainer held by the toner container holder in the corresponding tonercontainer insertion part.

According to another feature of the present invention, a toner supplyingdevice is provided for supplying toner contained in a toner containerattached to the toner supplying device to a developing device of animage forming apparatus. The device includes a first detect device thatdetects existence of toner being discharged from the opening of thetoner container inserted in each of the toner container insertion partsand a second detect device that detects in cooperation with the firstdetect device existence of an empty toner container inserted in thetoner container insertion parts. The second detect device includes adisplay device to indicate a detect result of the second detect device.The second detect device detects existence of an empty toner containerinserted in the toner container insertion parts by first detecting thata toner container in the toner container insertion parts has beenremoved and another toner container has been inserted, and thendetecting existence of toner being discharged from the another tonercontainer with the first detect device.

Further, a novel toner supplying device for supplying toner contained ina toner container attached to the toner supplying device to a developingdevice of an image forming apparatus, according to the presentinvention, includes a toner container detect device. The toner containerdetect device detects existence of the toner container inserted in thetoner insertion part and held by the toner container holder. Alsoincluded is toner detect device that detects existence of toner in thetoner container inserted in the toner insertion part and held by thetoner container holder. The toner supplying device is further providedwith a display device that displays an indication indicating results ofdetecting the existence of the toner container with the toner containerdetect device and the existence of toner in the toner container with thetoner detect device. The display device displays the indicationindicating results of detecting the existence of the toner containerwith the toner container detect device and the existence of toner in thetoner container with the toner detect device individually for each ofthe insertion inlets. The display device also displays separateindications indicating that the toner container exists and toner existsin the container, that the toner container exists and the container isrunning low on toner or is out of toner, and that no toner containerexists. The toner supplying device determines to supply toner or to stopsupplying toner to the developing device based upon a result ofdetecting an existence of the toner container with the toner containerdetect device and stops supplying toner to the developing device whenthe toner container detect device detects non-existence of the tonercontainer at least in one of the toner container insertion parts. Thetoner supplying device may further include a shutter for each of thetoner container insertion parts that opens and closes communicationbetween the toner container insertion parts and the toner conveyingpath. In addition, and the shutter closes or opens the communicationbetween the toner container insertion part and the toner conveying pathin accordance with a result of detecting with the toner container detectdevice existence of the toner container in a corresponding tonercontainer insertion part. The shutter closes the communication betweenthe toner container insertion part, in which no toner container isinserted, and the toner conveying path, and opens the communicationbetween the toner container insertion part, in which the toner containeris inserted, and the toner conveying path. The toner supplying devicemay further stop supplying toner to the developing device when the tonercontainer detect device detects non-existence of the toner container ineach of the toner container insertion parts. Further, an image formingapparatus including the toner supplying device, according to the presentinvention, may include a toner supply display device that displays anindication indicating results of detecting the existence of the tonercontainer with the toner container detect device and the existence oftoner in the toner container with the toner detect device.

According to another aspect of the present invention, a toner supplyingdevice for supplying toner contained in a toner container attached tothe toner supplying device to a developing device of an image formingapparatus, includes a toner container insertion part that detachablyaccommodates a toner container with an opening of the toner container todischarge toner therethrough being positioned at a rear end side of thetoner supplying device. Also included is an open/close device that opensand closes the opening of the toner container inserted in the tonercontainer insertion part by moving a cap of the toner container indirections to open and close the opening of the toner container,respectively. The open/close device includes a moving member to move thecap in the directions to open and close the opening of the tonercontainer, respectively. A drive device applies to the moving member ofthe open/close device a force to move the moving member in directions tomove the cap of the toner container inserted in the toner containerinsertion part in the directions to open and close the opening of thetoner container, respectively. The drive device is configured so as toprevent the moving member of the open/close device from being moved whenthe drive device does not apply the force to move the moving member. Theopen/close device may include a detect device that detects positions ofthe moving member to open and close the opening of the toner containerwith the cap of the toner container, respectively. The open/close devicemay also include a stepping motor, and the moving member is moved to thepositions to open and close the opening of the toner container with thecap by the force given to the moving member with the stepping motor.Further, the open/close device may include a shock absorbing member atpositions of the moving member to open and close the opening of thetoner container with the cap of the toner container, respectively. Thetoner supplying device of the present invention may further include atoner container removal preventing device that prevents a tonercontainer from being removed from the toner container insertion part incooperation with the moving member of the open/close device, when themoving member is in the position to close the opening of the tonercontainer with the cap of the toner container.

Furthermore, according to the present invention, an image formingapparatus including a toner supplying device is provided that suppliestoner contained in each of a plurality of toner containers attached tothe toner supplying device to the developing device with a holder thatdetachably holds the toner supplying device. The toner supplying deviceholder includes an opening for inserting the toner supplying device,that extends through an outer circumferential surface of the imageforming apparatus. The opening may be provided such that the tonersupplying device is inserted into and removed from the apparatus from afront side of the apparatus or a side of the apparatus where an exit toexit a copysheet is located. The toner supplying device holder includesa first guide member that is provided at the side of the toner supplyingdevice to guide the toner supplying device in a direction to be insertedinto and removed from the apparatus. The toner supplying device holdermay further include a second guide member provided on a circumferentialsurface of the image forming apparatus to guide the toner supplyingdevice in the directions to be inserted into and removed from theapparatus. The toner supplying device holder may also include apositioning member to position the toner supplying device in a positionto be attached to the image forming apparatus. In addition, the tonersupplying device may include a handhold, and a fixing device to fix thetoner supplying device to the apparatus.

Other objects, features and advantages of the present invention willbecome apparent from the following detailed description when read inconjunction with the accompanying drawings. Furthermore, while thedrawings and descriptions illustrate specific structures, the presentspecification clearly explains the function, concepts and attributes ofthe present invention in sufficient detail so as to make clear allpossible equivalent structures and techniques obtaining the desiredresult as discussed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and many of theattendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanyingdrawings, wherein:

FIG. 1 is a schematic drawing illustrating an example of an imageforming apparatus incorporating a toner supplying device according to anembodiment of the present invention;

FIG. 2 is a schematic drawing illustrating an example of an imageforming apparatus incorporating a toner supplying device according toanother embodiment of the present invention;

FIGS. 3 and 4 are schematic drawings illustrating a sectional view ofthe main part of the toner supplying devices incorporated in the imageforming apparatuses of FIGS. 1 and 2;

FIG. 5 is a flowchart illustrating an example of an operation ofcontrolling a regulating device that regulates and releases movement ofa cover covering a toner container insertion part of the toner supplyingdevices of FIGS. 1 and 2;

FIG. 6 is a detailed schematic drawing illustrating the construction ofthe image forming apparatus of FIGS. 1 and 2;

FIG. 7 is a sectional view illustrating a configuration of a powder pumpunit as a toner delivery device for transferring toner from a toner bankto the developing device in the image forming apparatuses of FIGS. 1 and2;

FIG. 8 is a schematic drawing illustrating the main portion of thedeveloping device of the image forming apparatus of FIG. 6 forexplaining control of toner supply from the toner bank to the developingdevice;

FIG. 9 is a schematic drawing illustrating a toner salvaging deviceattached to a toner supplying section of the developing device of theimage forming apparatus of FIG. 6;

FIG. 10 is a sectional view illustrating an example of a configurationof the developing device;

FIGS. 11(a) and 11(b) are schematic drawings illustrating a part of atoner container near an opening provided at an end part of thecontainer;

FIG. 12 is a series of schematic drawings for explaining how toner isdischarged from the toner container;

FIG. 13 is a schematic drawing illustrating an exemplary mechanism usedin the toner supplying device of FIGS. 1 and 2 for opening or closingthe opening at an end of the toner container with a cap;

FIG. 14 is a schematic drawing illustrating a state of theopening/closing mechanism when the cap is taken off to open the openingof the toner container;

FIG. 15 is a schematic drawing illustrating an exemplary construction ofa moving device that moves a chuck of the opening/closing mechanism toopen and close the opening of the toner container with the cap;

FIG. 16 is a schematic drawing illustrating a stopper that is used toprevent the toner container from being moved from the toner supplyingdevice;

FIG. 17 is a schematic drawing illustrating an example of an imageforming apparatus incorporating a toner supplying device according toanother embodiment of the present invention;

FIG. 18 is a schematic drawing illustrating an exemplary construction ofa toner discharging device used in the toner supplying device of FIG.17;

FIG. 19 is a schematic drawing illustrating an exemplary construction ofa toner delivery device used in the toner supplying device of FIG. 17;

FIG. 20 is a schematic drawing illustrating an outer appearance of animage forming apparatus incorporating another embodiment of a tonersupplying device according to the present invention;

FIG. 21 is a schematic drawing illustrating an image forming apparatusincorporating a toner supplying device according to another embodimentof the present invention;

FIG. 22 is a flowchart illustrating an exemplary operation of detectingan existence of an empty toner container in the toner containerinsertion part of the toner supplying device according to an embodimentof the present invention;

FIG. 23 is a schematic drawing illustrating a toner supplying deviceaccording to another embodiment of the present invention;

FIGS. 24(a), 24(b) and 24(c) are diagrams respectively illustrating anexample of an indication displayed in a display plane of a displaydevice of the toner supplying device of FIG. 23, respectively indicatingresults of detecting an existence of an empty toner container and anexistence of toner in each of the toner containers;

FIG. 25 is a flowchart of an operation of displaying an indication inthe display plane of the display device;

FIG. 26 is a schematic drawing illustrating a sectional view of a mainpart of the toner supplying device of FIG. 23;

FIG. 27 is a schematic drawing illustrating a sectional view of the mainpart of the toner supplying device when a toner container is notinserted in the toner insertion part;

FIG. 28 is a flowchart of an operation of displaying the indication thatno toner container exists in the corresponding toner container insertionpart, when a shutter to close the communication between an insertioninlet of the toner container insertion part and a toner conveying pathis provided in the toner supplying device;

FIG. 29 is a schematic drawing illustrating an example of an outerappearance of an image forming apparatus including the toner supplyingdevice of FIG. 23;

FIG. 30 is a sectional drawing illustrating the construction of theimage forming apparatus of FIG. 29;

FIGS. 31(a), 31(b), 31(c) and 31(d) are diagrams respectivelyillustrating another example of an indication of the display plane ofthe display device and a toner supply display plane of a toner supplydisplay device, respectively indicating results of detecting anexistence of an empty toner container and an existence of toner in eachof the toner containers;

FIG. 32 is a schematic drawing illustrating an exemplary construction ofthe toner delivery device used in the toner supplying device of FIG. 23;

FIG. 33 is a schematic drawing illustrating the main portion of thedeveloping device of the image forming apparatus of FIG. 30 forexplaining control of toner supply from the toner supplying device tothe developing device;

FIG. 34 is a flowchart illustrating an exemplary operation of detectingan existence of an empty toner container and an existence of toner ineach of the toner containers and displaying detect results in thedisplay plane;

FIG. 35 is a schematic sectional drawing illustrating an example of atoner supplying device according to another embodiment of the presentinvention;

FIG. 36 is a schematic drawing illustrating an image forming apparatusincorporating the toner supplying device of FIG. 35;

FIG. 37 is a schematic sectional drawing illustrating an example of atoner supplying device according to still another embodiment of thepresent invention;

FIG. 38 is a schematic drawing illustrating an image forming apparatusincorporating the toner supplying device of FIG. 37;

FIGS. 39 and 40 are sectional drawings illustrating a structure of atoner insertion part and an open/close device used in the tonersupplying devices of FIGS. 35 and 37;

FIG. 41 is a schematic drawing illustrating a structure of a drivedevice to drive the open/close device used in the toner supplyingdevices of FIGS. 35 and 37;

FIGS. 42(a) and 42(b) are schematic drawings illustrating anotherexample of the open/close device;

FIG. 43 is a schematic drawing illustrating still another example of theopen/close device;

FIG. 44 is a schematic drawing illustrating still another example of theopen/close device;

FIG. 45 is a schematic drawing illustrating an example of a constructionof an operation lever used in the toner supplying device of FIGS. 35 and37;

FIG. 46 is a detailed schematic drawing illustrating the structure ofthe operation lever;

FIG. 47 is a schematic drawing illustrating an example of a lockingmember for the operation lever;

FIG. 48 is a schematic drawing illustrating an example of an imageforming apparatus including a toner supplying device according toanother embodiment of the present invention; and

FIG. 49 is a schematic drawing illustrating an example of an imageforming apparatus including a toner supplying device according toanother embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In describing preferred embodiments of the present invention illustratedin the drawings, specific terminology is employed for the sake ofclarity. However, the present invention is not intended to be limited tothe specific terminology so selected and it is to be understood thateach specific element includes all technical equivalents which operatein a similar manner.

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, and moreparticularly to FIG. 1 thereof, there is illustrated an overall view ofa configuration of an image forming apparatus incorporating a tonersupplying device according to an exemplary embodiment of the presentinvention.

In FIG. 1, an image forming apparatus 100 includes an image carrier 10and a developing device 9 at an upper right part of the apparatus 100 inthe drawing. A toner bank 20 as a toner supplying device is arranged ata lower left part of the apparatus 100, apart from the developing device9, in this embodiment. The toner bank 20 is configured such that twopieces of a toner container 1, each containing toner therein, can beattached to the toner bank 20 from a front side 20a of the toner bank20. Two toner container insertion parts 2 that respectively receive atoner container 1 are arranged vertically, and a toner insertion inlet2a is opened at the front side 20a of the toner bank 20 for each tonerinsertion part 2 as illustrated in the drawing. The toner container 1 isinserted into the toner insertion part 2 in a direction indicated by anarrow A through the toner insertion inlet 2a and then held by a tonercontainer holder 3.

When the toner container 1 is held by the toner container holder 3,toner (T) contained in the container 1 is discharged through an opening1a, which is provided at an axial end of the container 1 in thedirection in which the container 1 is inserted into the toner containerinsertion part 2, to a toner exhaust path 4 which is provided at a rearend side of the toner container insertion part 2. Then, the dischargedtoner is mixed with air by a toner delivery device 5 and conveyed to thedeveloping device 9 via a toner/air mixture conveying path 8.

The toner bank 20 includes a cover 6 as a covering device to cover theentire surface of the front side 20a of the toner bank 20, including thetoner container insertion parts 2. The cover 6 is configured so as toswing open and close to cover and uncover the surface of the front side20a of the toner bank 20. The cover 6 is arranged so as to be free froma front cover 100b of the image forming apparatus 100, which covers apart of the apparatus 100 containing the image carrier 10 and thedeveloping device 9. When the cover 100b is opened, the apparatus 100stops an image forming operation. The cover 6 is held at one side so asto open and close in a direction indicated by an arrow C. Further, aregulating device 7 is arranged so as to regulate the movement of thecover 6 to open and close. The regulating device 7 includes a magnet 7a,which regulates the movement of the cover 6 to open and close andreleases the regulation of the movement of the cover 6 to open andclose.

FIG. 2 is a schematic drawing illustrating an example of an imageforming apparatus incorporating a toner supplying device according toanother embodiment of the present invention. An image forming apparatus100 includes an image carrier 10 and a developing device 9 at an upperright part of the apparatus 100 in the drawing. A toner bank 30 as atoner supplying device is arranged at a lower left part of the apparatus100, apart from the developing device 9.

The toner bank 30 is configured such that three pieces of a tonercontainer 1, each containing toner therein, can be attached to the tonerbank 30 from a front side 30a of the toner bank 30. Specifically, threetoner container insertion parts 2-1, 2-2 and 2-3 that respectivelyreceive a toner container 1 are arranged vertically, and a tonercontainer insertion inlet 2a is opened at the front side 30a of thetoner bank 30 for each of the toner insertion parts 2-1, 2-2 and 2-3 asillustrated in the drawing. The toner container 1 is inserted into eachof the toner insertion parts 2-1, 2-2 and 2-3 in a direction indicatedby an arrow A through each toner insertion inlet 2a and then held by atoner container holder 3.

When the toner container 1 is held by the toner container holder 3 andis operated to discharge toner therefrom, toner (T) contained in thecontainer 1 is discharged through an opening 1a. The opening 1a isprovided at an axial leading end of the container 1 in the direction inwhich the container 1 is inserted into each of the toner containerinsertion parts 2-1, 2-2 and 2-3. The toner is thus discharged into atoner exhaust path 4 provided at a rear end side of the toner containerinsertion parts 2-1, 2-2 and 2-3. Then, the exhausted toner is mixedwith air by a toner delivery device 5 and is conveyed to the developingdevice 9 via a toner/air mixture conveying path 8.

The toner bank 30 includes covers 6a, 6b and 6c that respectively coverthe surfaces of the front side 30a of the toner bank 30, including thetoner container insertion parts 2-1, 2-2 and 2-3. The covers 6a, 6b and6c are respectively configured so as to swing open and close, such thatthe surfaces of the front side 30a of the toner bank 30 are covered anduncovered by the covers 6a, 6b and 6c, respectively. The covers 6a, 6band 6c are arranged so as to be free from a front cover 100b of theimage forming apparatus 100, which covers the part of the apparatus 100containing the image carrier 10 and the developing device 9. When thecover 100b is opened, the image forming apparatus 100 stops the imageforming operation. The covers 6a, 6b and 6c are held at one side so asto open and close in a direction indicated by an arrow C, respectively.Further, a regulating device 7 is arranged for each of the covers 6a, 6band 6c so as to regulate movement of the covers 6a, 6b and 6c to openand close, respectively. The regulating device 7 for each of the covers6a, 6b and 6c includes a magnet 7a, which regulates the movement of thecovers 6a, 6b and 6c to open and close and releases the regulation ofthe movement of the covers 6a, 6b and 6c to open and close,respectively.

FIGS. 3 and 4 are schematic drawings illustrating a sectional view of amain part of the toner banks 20 and 30, respectively. As illustrated inthe drawings, the regulating device 7 for the cover 6 in the toner bank20 and the regulating device 7 for each of the covers 6a, 6b and 6c ofthe toner bank 30 respectively further include a locking device 7b thatregulates and releases movement of the cover 6 of the toner bank 20 andthe covers 6a, 6b and 6c of the toner bank 30.

The locking device 7b includes a crank-like shaped member 7b1, which isprovided to the cover 6 of the toner bank 20 and to each of the covers6a, 6b and 6c of the toner bank 30. Also included is an engaging member7b3, which engages with and disengages from the crank-like shaped member7b1 by a rotation movement of a motor 7b2, which is provided at the sideof the toner banks 20 and 30, respectively.

Referring to FIG. 3, when the toner container 1 is discharging toner (T)through the opening 1a to the toner exhaust path 4, a controller 12controls the crank-like shaped member 7b1 and the engaging member 7b3 tobe engaged with each other by the rotation movement of the motor 7b2,such that the cover 6 of the toner bank 20 and each of the covers 6a, 6band 6c of the toner bank 30 do not open. When the toner container 1 isnot discharging toner through the opening 1a to the toner exhaust path4, the controller 12 controls to release the engagement of thecrank-like shaped member 7b1 and the engaging member 7b3 by the rotationmovement of the motor 7b2, such that the cover 6 and each of the covers6a, 6b and 6c can be opened in a direction indicated by an arrow H, asillustrated in FIG. 4.

FIG. 5 is a flowchart illustrating an example of an operation ofcontrolling the regulating device 7 with the control device 12. Step S1determines if a toner container 1 is inserted and set in each of thetoner container insertion parts 2 in the toner bank 20 and in each ofthe toner container insertion parts 2-1, 2-2 and 2-3 in the toner bank30. When the answer to the step S1 is No, in the toner bank 20, theengagement of the crank-like shaped member 7b1 and the engaging member7b3 for the cover 6 for the toner container insertion part 2 is released(Step S2), such that the cover 6 can be opened. In the toner bank 30,the engagement of the crank-like shaped member 7b1 and the engagingmember 7b3 for the cover 6a, 6b or 6c for the toner container insertionpart 2-1, 2-2 or 2-3, in which a toner container 1 is not inserted, isreleased such that the corresponding cover 6a, 6b or 6c can be opened.

When the answer to the step S1 is Yes, step S3 determines if toner (T)is being discharged from each of the toner containers 1 through eachopening 1a to the toner exhaust path 4. In the toner bank 20, when toneris not being discharged from one of the toner containers 1, theengagement of the crank-like shaped member 7b1 and the engaging member7b3 for the cover 6 for the toner container insertion part 2 isreleased, such that the cover 6 can be opened. In the toner bank 30,when toner is not being discharged from any one of the toner containers1, the engagement of the crank-like shaped member 7b1 and the engagingmember 7b3 for the cover 6a, 6b or 6c for the corresponding tonercontainer insertion part 2-1, 2-2 or 2-3 is released, such that thecorresponding cover 6a, 6b or 6c can be opened.

When toner is being discharged from one of the toner containers 1 in thetoner bank 20, the crank-like shaped member 7b1 and the engaging member7b3 for the cover 6 for the toner container insertion part 2 iscontrolled to be engaged with each other in step S4 such that the cover6 cannot be opened. In the toner bank 30, when toner is being dischargedfrom any one of the toner containers 1, the crank-like shaped member 7b1and the engaging member 7b3 for the cover 6a, 6b or 6c for thecorresponding toner container insertion part 2-1, 2-2 or 2-3 iscontrolled to be engaged with each other such that the correspondingcover 6a, 6b or 6c cannot be opened.

FIG. 6 is a schematic drawing illustrating in more detail theconstruction of the image forming apparatus 100 of FIG. 2. The imageforming apparatus 100 is a copying machine and includes an automaticdocument feeder (ADF) 110, an exposing section 120 for forming an imagein a conventional known electrophotographic system, an image formingsection 130, and a paper feeding section 140. The exposing section 120has an exposure optical system including a light source 121 for puttinglight on a document (D) placed on a contact glass 111 by the ADF 110 orwith a manual insertion, a series of mirrors 122 and a lens 123 forusing a reflected light image from the document to expose a surface of aphotosensitive drum 10, which is a latent image carrier of the imageforming section 130.

The image forming section 130 has the photosensitive drum 10 as theimage carrier, and a charging device 13, a developing device 9, a resistroller 14, a transfer device 11 and a photosensitive body cleaningdevice 15, which are arranged around the photosensitive drum 10. Alsoincluded is a fixing device 16, a paper output roller 17, a transferpaper reversing/delivering section 18 for duplex copying, and a paperoutput tray 19. In the paper feed section 140, a plurality of paper feedcassettes are set containing transfer paper (P) in various sizes.Although the above exposing section 120 is an example of an analog-typeexposure optical system, it can serve as a laser printer if it isconfigured in a system in which an image is optically recorded on thephotosensitive drum 10 based on an image signal by using a laser scanoptical system in which a laser light source and a deflector are used asan exposing section. The exposing section can also serve as a digitalcopying machine or a facsimile if a document reader is arranged betweenthe ADF 110 and the exposing section 120.

In FIG. 6, when an image forming operation is started, thephotosensitive drum 10 is charged by the charging device 13 and thenexposed for a document image from the exposing section 120 so that astatic latent image is formed on it. The static latent image isdeveloped by developer (e.g., two-component developer or one-componentdeveloper) in the developing device 9, and a toner image is formed onthe photosensitive drum 10. A toner image formed on the photosensitivedrum 10 is transferred to a transfer paper (P) fed to a transfer section(i.e., a nip portion between the photosensitive drum 10 and the transferbelt 11a of the transfer device 11) through the resist roller 14 fromthe paper feed section 140. The transfer paper (P) to which the tonerimage is transferred is delivered to the fixing device 16 by thetransfer belt 11a of the transfer device 11, and the toner image isfixed to the transfer paper (P) by the fixing device 16. The fixedtransfer paper (P) is output to the paper output tray 19 via the paperoutput roller 17. The photosensitive drum 10, after transferring thetoner image, is cleaned by the photosensitive body cleaning device 15 tosalvage or remove remaining toner and contaminants, such as paper lint.The transfer belt 11a, after transfer paper delivery, is also cleaned bya cleaning device 11b in the transfer device 11 to salvage or removeremaining toner and paper lint.

In FIG. 6, as the developing device 9, there is shown an example inwhich a magnetic brush developing method using a two-component developerincluding toner (T) and a carrier is applied.

Apart from the developing position of the developing device 9, the tonerbank 30 as a toner supplying device is provided. In this embodiment, thetoner bank 30, including a plurality of toner container insertion parts2-1, 2-2 and 2-3, is positioned at a lower left part of the imageforming apparatus 100. The toner bank 30 may alternatively be positionedat a lower right part of the image forming apparatus 100 or in otherappropriate places.

The toner bank 30 is connected to the developing device 9 via a flexibletoner conveying pipe as the toner/air mixture conveying path 8 throughwhich toner is conveyed while being mixed with air. Toner stored in eachof the toner containers set in the toner bank 30 is supplied to thedeveloping device 9 through the toner/air mixture conveying path 8 by apowder pump unit as a toner delivery device 5. As shown in FIG. 6, inthis embodiment, the powder pump unit as the toner delivery device 5 isarranged in a lower portion of the toner bank 30.

The toner container 1 is inserted into each of the toner insertion parts2-1, 2-2 and 2-3 in a direction indicated by an arrow A from the side ofthe front surface 30a with an opening 1a as the leading edge so as to beattached to the toner bank 30. A regulating device 7 regulates andreleases an opening and closing movement of a cover 6 covering thesurface of the toner bank 30.

For the toner/air mixture conveying pipe as the toner/air mixtureconveying path 8, it is advantageous to use a material which is flexibleand has excellent resistance to toner, such as, for example, nylon,Teflon, etc. In the image forming apparatus 100 in this embodiment, theconnection between the developing device 9 and the toner bank 30 isflexible, whereby a restriction on each arrangement is dissolved, andtherefore it is possible to utilize the layout effectively. Further,because each of the toner containers 1 is inserted into the tonercontainer insertion parts 2-1, 2-2 and 2-3 from the front side of theapparatus 100, with the opening 1a as the leading edge, the operation ofattaching and detaching the toner container 1 to and from the toner bank30 is facilitated and scattering of toner is minimized.

FIG. 7 is a sectional view showing a configuration of the powder pumpunit as the toner delivery device 5 for transferring toner from thetoner bank 30 to the developing device 9. Toner exited from the tonercontainer 1 to the toner exhaust path 4 is deposited in a hopper 5k andthe deposited toner is then conveyed by the powder pump unit 5 to thedeveloping device 9. For the powder pump unit 5, a screw pump which isconventionally known and commonly called a Moineau-pump is used. Asshown in FIG. 7, the power pump unit 5 includes a rotor 5a, a stator 5b,and a holder 5c.

The rotor 5a is engaged with a driving source, such as a driving motor(not shown) via a driving shaft 5d (or in some cases a horizontaldelivery screw with a screw attached to the driving shaft on its outerperiphery), and the rotor 5a is rotatively driven by a rotation of thedriving source. The stator 5b is made of an elastic body, such as arubber material, and surrounds the rotor 5a. The holder 5c holds thestator 5b.

The toner delivery device 5 takes in toner at the bottom part of thetoner bank 30 from the side of the driving shaft 5d to deliver the tonertoward a toner passageway (i.e., discharging section) 5f with a rotationof the rotor 5a. In addition, there is about a 1-mm gap 5e between aside of the stator 5b and an inner side of the holder 5c forcommunication with the toner passageway 5f. An air supply port 5g isprovided so that an air blows from the gap 5e to the toner passageway5f. The air supply port 5g communicates with the toner passageway 5f,and further communicates with an air exhaust outlet 5i of an air pump asan air supplying device 5h via an air supply tube 5j. When the air pump5h starts to run, air blows on the toner (T) in the toner passageway 5fvia the air supply tube 5j and the air supply port 5i by approximately0.5 to 1 liter/minute of a blow amount, whereby fluidization isaccelerated for toner that is discharged from the toner passageway 5f ofthe powder pump unit 5. Thus, the toner is discharged to the tonerconveying pipe 8 while being mixed with air. Therefore, toner deliverywith the powder pump 5 becomes more reliable.

FIG. 8 is a schematic drawing illustrating the main portion of thedeveloping device 9 for explaining control of toner supply from thetoner bank 30 to the developing device 9. The toner supply from thetoner bank 30 to the developing device 9 in this embodiment is performedby a sensor as a toner detect device 9a arranged in the developingdevice 9 and a controller (not shown).

If the sensor 9a does not detect the toner, that is, when the height ofthe accumulated toner in the toner supplying section 9b of thedeveloping device 9 is lower than a predetermined level, the abovepowder pump unit 5 is driven to supply toner from the toner bank 30 tothe toner supplying section 9b of the developing device 9. When theheight of the accumulated toner in the toner supplying section 9breaches the predetermined level, the toner is detected by the sensor 9aand the supplying of toner to the toner supplying section 9b from thetoner bank 30 is stopped. With these controls, the toner supplyingsection 9b always contains a certain amount of toner, so that a stabledeveloping process is assured. Additionally, if the sensor 9a dose notdetect the toner a predetermined number of times (i.e., at periodic orpredetermined intervals) or for a predetermined period of time, it isdetermined that toner contained in the operating toner container 1 isalmost exhausted. Then, toner contained in another toner container 1starts to be discharged to be conveyed to the toner supplying section 9bof the developing device 9. In the toner supplying section 9b of thedeveloping device 9, as shown in FIG. 8, a toner supplement opening 9dis formed in the side of an axial end of a stirring member 9c arrangedin the toner supplying section 9b, and in this toner supplement opening9d, a toner salvaging device 9e described next is removably attached.

FIG. 9 is a schematic drawing illustrating an example of the tonersalvaging device 9e attached to the toner supplying section 9b of thedeveloping device 9. The toner salvaging device 9e has a unit structurethat is configured separately from the developing device 9. The tonersalvaging device 9e is used to salvage toner that has been deliveredwhile being mixed with air through the toner/air mixture conveying path8 from the toner bank 30 by separating the toner (T) from the air, so asto supply the toner in preparation for decreased supplement toner in thetoner supplying section 9b of the developing device 9.

In FIG. 9, the toner salvaging device 9e has a funnel-shaped tonerseparating section 9e1 whose longer direction is vertical. The tonerseparating section 9e1 includes a hopper that separates air from tonertransmitted from the toner bank 30, and drops only the toner by gravity,so as to put the toner into the toner supplying section 9b of thedeveloping device 9. Therefore, in the upper part of the tonerseparating section 9e1, an end of the toner/air mixture conveying path8, through which the toner is delivered from the toner bank 30, isconnected, while an opening 9e2, which can be connected to the tonersupplying section 9b of the developing device 9, is formed in the lowerpart. With this configuration, a mixture of air and toner transmittedfrom the toner/air mixture conveying path 8 falls spiraling, whenstriking an inner wall of the toner separating section 9e1, due to theshape of the toner separating section 9e1 and the discharging positionof the toner/air mixture conveying path 8. The air having a lowerspecific gravity rises, while the toner having a higher specific gravitydrops, and thus the air is separated from the toner. On the top surfaceof the toner separating section 9e1, there is included a filter 9e3 fordischarging only air, and on the bottom surface, there is provided anopening/closing member 9e4 for opening or closing the opening 9e2.

Next, the developing device 9 will be described below. FIG. 10 is asectional view illustrating an example of a configuration of thedeveloping device 9. In FIG. 10, the developing device 9 has adeveloping container 9f and the toner supplying section 9b. Thedeveloping container 9f is arranged near the photosensitive drum 10,which is a latent image carrier movable in a direction indicated by anarrow B in the drawing. The toner supplying section 9b is mounted on thedeveloping container 9f In the developing container 9f, a stirringroller 9g and a paddle wheel 9h are arranged for development, so as toscoop up a two-component developer having magnetic or non-magnetic tonerand magnetic carrier subjected to frictional electrification in oppositepolarities by being stirred and mixed by the stirring roller 9g and thepaddle wheel 9h. In addition, the toner supplying section 9b stirs thetoner (T) with a rotation of a toner supplying roller 9b1 and transmitsit toward the stirring roller 9g if a density of the toner supplied tothe photosensitive drum 10 is lowered.

In a position where the developer is scooped up by the paddle wheel 9h,there are arranged a plurality of (e.g., two shown in the drawing)developing rollers 9i and 9j near the photosensitive drum 10. The twodeveloping rollers 9i and 9j are arranged in the upstream side and thedownstream side along a moving direction of the photosensitive drum 10.The roller in the upstream side is considered to be a first developingroller 9i and the roller in the downstream side is to be a seconddeveloping roller 9j. The first and second developing rollers 9i and 9jinclude a developing sleeve that is rotatable in a counterclockwisedirection in the drawing by a driving section (not shown) and a magneticroller fixed in the developing sleeve as the main portion. Thisdeveloping sleeve is made of a non-magnetic body, such as aluminum orstainless steel. The magnetic roller includes a plastic magnet molded bymixing a ferrite magnet or a rubber magnet, and further nylon powder andferrite powder, having a configuration in which a plurality of magneticpoles are arranged along a circumferential direction.

In the developing container 9f, the developer is scooped up by acentrifugal force generated at a rotation of the paddle wheel 9h andthen expelled toward the first developing roller 9i. A part of theexpelled developer is supplied directly to the first developing roller9i and carried on a surface of the first developing roller 9i. Anotherpart of the remaining developer to be expelled rebounds from the seconddeveloping roller 9j and then is carried on the surface of the firstdeveloping roller 9i by way of a magnetic force in the side of the firstdeveloping roller 9i. To supply the developer to the first developingroller 9i also from the side of the second developing roller 9j, it isdesired to increase a relative rotation speed of the paddle wheel 9h inorder to increase the amount of developer rebounding from the seconddeveloping roller 9j so as to increase the centrifugal force in advance.

The developer carried on the surface of the first developing roller 9imoves on the roller surface with a rotation of the developing sleeve,and after the layer thickness is restricted by a doctor blade 9k, itreaches a first developing area D1 in which the first developing roller9i is opposite to the photosensitive drum 10, so that a latent image onthe photosensitive drum 10 is made visible with toner. Then thedeveloper, which has passed the first developing area D1 moves to aposition where the magnetic force in the side of the first developingroller 9i has a lower effect. Thus, the developer is transmitted towarda second developing area D2 between the second developing roller 9j andthe photosensitive drum 10, as indicated by a dashed line in thedrawing, with a rotation in the side of the second developing roller 9jand a magnetic force from the magnetic roller. Then, the developer dropsto the bottom of the developing container 9f in a position where thesecond developing roller 9j has no effect, and the developer is stirredagain by the paddle wheel 9h.

On the other hand, developer scraped off by the first developing roller9i, due to restriction of the layer thickness with the doctor blade 9k,is guided by a separator 9l toward a delivery screw 9m located at theother end of an extension of the separator 9l. The developer is thendropped on the stirring roller 9g by the delivery screw 9m. Therefore,at the other end of the extension of the separator 9l, there is a slitfor dropping the developer formed in a position opposite to the stirringroller 9g.

The magnetic rollers arranged in the first and second developing rollers9i and 9j have an arrangement of magnetic poles, which can be used toform a repulsion magnetic field generated by the identical poles betweenthe nearest portions of the first developing roller 9i and the seconddeveloping roller 9j, so that the transfer direction of the developer isforcibly set to a direction in which the developer starts for the seconddeveloping roller 9j. With this arrangement, the developer istransferred to the second developing roller 9j by the magnetic pole inthe side of the second developing roller 9j.

Near the stirring roller 9g in the developing container 9f, there isarranged a toner density sensor as a toner density detecting device 9nfor detecting a mixing ratio of toner and carrier. The toner densitysensor 9n employs, for example, a method in which a toner density isdetected based on a content of the toner in the developer by usingchanges of inductance on a coil arranged in the developer.

FIGS. 11(a) and 11(b) are schematic drawings illustrating a part of thetoner container near the opening 1a. As illustrated in the drawings, ashoulder part 101 is formed at an end part 102 holding the opening 1a.In addition, a spiral groove or protrusion is formed inside thecontainer 1 toward the opening 1a. Because of this configuration, therotation of the container 1 in a direction I causes toner contained inthe container 1 to be conveyed by the spiral groove or protrusion towardthe opening 1a through the shoulder part 101 and discharged from thecontainer 1.

FIG. 12 illustrates how toner is discharged from the toner container 1.Sub-diagrams (a1), (b1), (c1) and (d1) are elevation views of the tonercontainer 1 and sub-diagrams (a2), (b2), (c2) and (d2) are correspondingright-side views of the toner container 1. The sub-diagrams (b1)(b2)show views rotated from the sub-diagram (a1)(a2) by 90 degrees, thesub-diagrams (c1)(c2) show views rotated from the sub-diagrams (b1)(b2)by 90 degrees, and the sub-diagrams (d1)(d2) show views rotated from thesub-diagrams (c1)(c2) by 90 degrees, respectively. λ₁ -λ₄ are used toillustrate 90° rotations of the toner container 1.

As shown, the toner container 1 is formed with the opening 1a fordischarging toner at an end of a cylindrical container body 1b so as tohave a smaller diameter than a diameter of the cylindrical body 1b.Further, with a part of the inner surface of the shoulder part 101 ofthe end part 102 on which the opening 1a of the toner container 1 isformed being pushed out from the inner surface of the shoulder part 101up to an edge of the opening 1a, a projected portion 1c for raisingtoner is formed.

Specifically, the sub-diagrams (a2), (b2), (c2) and (d2) show how toneris guided by the projected portion 1c of the toner container 1 and anopening projected portion 1d. An arrow B in each sub-diagram indicates adirection in which the toner container 1 rotates. In the sub-diagrams(a1) and (a2), each part of the maximum diameter in the shoulder part101 is located vertically downward and toner is guided to the lower partof the circumferential wall in the maximum-diameter part of a headportion of the toner container 1 by a guiding groove 1e. In the stateshown in the sub-diagrams (b1) and (b2), after a rotation by 90 degreesfrom the above state in a direction indicated by the arrow D, aborderline area between the maximum-diameter part of the shoulder part101 and the projected portion 1c are located vertically downward and apart of the toner guided by the above guiding groove 1e is put on theprojected portion 1c. During a further rotation by 90 degrees from thisstate to the state shown in the sub-diagrams (c1) and (c2) in adirection indicated by the arrow D, the projected portion 1c raises thetoner up to an edge of the opening 1a as if it were a spoon. Before orafter the state shown in the sub-diagrams (d1) and (d2) after a furtherrotation by 90 degrees in a direction indicated by the arrow D, theabove toner on the projected portion 1c is partially transferred to theopening projected portion 1d and then discharged from the opening 1a dueto an incline of the opening projected portion 1d. In this point, theprojected portion 1c itself is recessed like a scooping part of a spoonas apparently shown in the sub-diagram (c2) in this example. By using atoner container having this shape near the opening 1a, it is possible toprevent a discharge and a drop of a lump of toner, and also to preventscattering of toner powder dust in the toner deposit portion at thebottom of the toner bank 30. Thus, the toner is gradually dischargedfrom the toner container 1 through the opening 1a. In addition, it ispossible to use almost the entire amount of toner contained in the tonercontainer 1, without leaving some of the toner. Furthermore, extra toneris removed by the rotation of the toner container 1 and only a spoonfulof toner is scooped up to the opening 1a, and therefore toner isdischarged stably from the opening 1a.

Next, an exemplary mechanism for opening and closing the opening 1a atan end of the toner container 1 with a cap is described with referenceto FIG. 13.

FIG. 13 illustrates the toner container 1 being set in a holder portion3a of the toner container holder 3 of the toner bank 30 and the opening1a being closed with a cap 3g. In the holder portion 3a, there isprovided a rotatably-supported inner holder 3c in a holder 3b. The innerholder 3c is rotated by a gear drive (not shown) via a driving gear 3c1.The toner container 1 has recess and projecting portions (not shown) sothat it can rotate synchronously with this inner holder 3c. In the innerholder 3c, a seal 3d is arranged so as to prevent toner from beingscattered from a gap between the toner container 1 and a supportingsection of the inner holder 3c. In the holder 3b, a slider 3e and achuck 3f are supported so as to respectively slide freely.

The slider 3e is pressed by a spring 3h in a direction that urges thecap 3g toward the toner container 1. When the chuck 3f is shifted in adirection indicated by an arrow F from this state, as shown in FIG. 13,a grab portion 3i of the cap 3g is held by a click 3f1 of the chuck 3fand then the cap 3g is drawn out of the toner container 1, whereby theopening 1a is opened.

FIG. 14 is a schematic drawing illustrating a state of theopening/closing mechanism when the cap 3g of the toner container istaken off to open the opening 1a. In FIG. 14, when the driving gear 3c1is rotated by a gear of the rotation driving device 3j in this state,the inner holder 3c rotates and the toner container 1 rotatessynchronously with this rotation, whereby toner (T) in the tonercontainer 1 is discharged from the opening 1a. If the toner (T)remaining in the toner container 1 becomes less than a predeterminedamount, as determined by the toner detect device 9a after apredetermined period of time sufficiently long for using up theremaining toner of the toner container 1, the opening 1a of the tonercontainer 1 is closed by the cap 3g by shifting the chuck 3f with amoving device 3k in a direction indicated by the arrow G in FIG. 14.

FIG. 15 is a schematic drawing illustrating an exemplary construction ofthe moving device 3k. As shown in FIG. 15, the moving device 3k includesa driving motor 3k1, a worm gear 3k2, a helical gear 3k3, a pinion 3k4,and a rack 3k5. The chuck 3f is moved in a horizontal direction asindicated by an arrow H in the drawing with a rotation of the drivingmotor 3k1 in a clockwise direction or a counterclockwise direction,whereby the cap 3g can be put on or taken off the opening 1a of thetoner container 1. When the cap 3g is put on the opening 1a of the tonercontainer 1, a stopper (illustrated in FIG. 16) is used to prevent thetoner container 1 from being moved.

In FIG. 16, a stopper 31 is supported by a stepped screw 3m and a spring3n so as to be fixed to the holder 3b, with its click portion beingengaged with a projection arranged on an outer peripheral surface of thetoner container 1. The stopper 31 is pressed by the spring 3n so as notto be raised up to the position indicated by a two-dotted and dashedline in FIG. 16 by a force of closing the cap 3g. Accordingly, the cap3g can be put on the opening 1a of the toner container 1 securely. Inaddition, when exchanging the toner container 1, the toner container 1can be easily removed from the stopper 3l, so that it can be easilyexchanged. This may be accomplished by pulling out the toner container 1more strongly or by withdrawing the stopper 3l manually or with an addedlever or the like to the position indicated by the two-dotted and dashedline in FIG. 16.

FIG. 17 is a schematic drawing illustrating an example of an imageforming apparatus incorporating a toner supplying device according toanother embodiment of the present invention. An image forming apparatus100 includes a toner supplying device 40, an automatic document feeder(ADF) 110, an exposure unit 120, an image forming unit 130, a paperfeeding unit 140 and so on for forming an image using a knownelectrophotography.

In this embodiment, the toner supplying device 40 is arranged, apartfrom the developing position where a developing device 9 and an imagecarrier 10 face each other, at a lower left part of the apparatus 100 inthe drawing. A toner container insertion part 2 is configured so as toaccommodate a plurality of toner containers 1. The toner containerinsertion part 2 is provided with a plurality of insertion inlets, suchthat a toner container 1 is inserted into each of the inlets, from afront side of the toner supplying device 40 to be set in the tonercontainer insertion part 2. A cover 6 is held at one side of the tonersupplying device 40 so as to open and close the front surface of thetoner supplying device 40, in which the insertion inlets are provided. Atoner discharging device 43 causes the toner container 1 set in thetoner container insertion part 2 to discharge toner through an opening1a of the toner container 1 to a toner conveying path 410 communicatingwith the opening 1a of each toner container 1. A first detect device 44to detect toner being discharged through the opening 1a of the tonercontainer 1 is arranged for each toner container 1 in the tonerconveying path 410 communicating with the opening 1a of each tonercontainer 1. More specifically, an upper first detect sensor 44a isarranged for the toner container 1 set at the top of the toner insertionpart 2, a middle first detect sensor 44b for the toner container 1 atthe middle, and a bottom first detect sensor 44c for the toner container1 at the bottom of the toner container insertion part 2. Further, asecond detect device 45 is arranged for each toner container 1 so as todetect, in cooperation with the first detect device 44, existence of anempty toner container 1 inserted in the toner container insertion part2. The second detect device 45 includes an upper second detect sensor45b1, a middle second detect sensor 45b2 and a lower second detectsensor 45b3, respectively arranged for the corresponding toner container1 inserted in the toner container insertion part 2.

The toner supplying device 40 is connected to the developing device 9via a toner/air mixture conveying path 8, which is typically made of aflexible pipe. A toner delivery device 5 is arranged at a bottom part ofthe toner supplying device 40 to deliver toner (T), which is exhaustedto the toner conveying path 410 from each toner container 1 and conveyedto a merged conveying path 41l, to a toner supplying part 9b of thedeveloping device 9 via the toner/air mixture conveying path 8. Thetoner delivery device 5 includes a powder pump which is generally calleda Moineau pump.

As a latent image on the image carrier 10 is developed with toner to beformed as a toner image by the developing device 9, the toner in thedeveloping device 9 is consumed and the amount of toner in thedeveloping device 9 decreases. As the amount of toner in the developingdevice 9 decreases, toner in the toner supplying part 9b is supplied tothe developing device 9. If the amount of toner in the toner supplyingpart 9b decreases below a predetermined level, a toner detect sensor 9aarranged in the toner supplying part 9b detects the decrease of toner inthe toner supplying part 9b. A controller (not shown) then controls thetoner discharging device 43 to rotate the operating toner container 1 todischarge toner while driving the toner delivery device 5, such thattoner is conveyed to the toner supplying part 9b via the toner/airmixture conveying path 8.

While the operating toner container 1, (e.g., the toner container 1 atthe top of the toner container insertion part 2), is discharging toner,the upper first detect sensor 44a detects existence of the toner beingexhausted from the operating toner container 1. If the upper firstdetect sensor 44a detects non-existence of the toner being dischargedfrom the operating toner container 1, the controller (not shown)determines that the operating toner container 1 has run out of the tonerand activates, for example, the toner container 1 at the middle of thetoner insertion part 2 to discharge toner therefrom. In addition, atsubstantially the same time, a display device 45a arranged at a part ofthe toner supplying device 40 of the image forming apparatus 100,displays a message indicating that the toner container 1 at the top hasrun out of toner or produces a sound so as to remind an operator toreplace the used toner container 1 at the top.

Thus, even if one of the plurality of toner containers 1 has run out oftoner, toner is supplied from another toner container 1, and thereby thetoner is not intermittently supplied to the developing device 9.Further, by replacing the used toner container 1 in accordance with themessage or the reminding sound, stoppage of the image forming operationis prevented.

However, when replacing the used toner container 1, the operator mayerroneously attach an empty toner container 1. Therefore, a controller45c for the second detect device 45 is configured so as to control thesecond detect device 45 to repeat the detect operation when a new tonercontainer 1 is set to the toner container insertion part 2.Specifically, when the new toner container 1 is set in the tonercontainer insertion part 2, the newly set toner container 1 is rotatedso as to exhaust the toner therefrom. If the first detect device 44detects non-existence of toner again (i. e, the newly set tonercontainer 1 is empty), then the display device 45a again displays themessage or produces the sound reminding the operator to replace theempty toner container 1. If the first detect device 44 detects existenceof toner, the message in the display device 45a or the sound produced bythe display device 45a is not activated.

Further, if power to a power supply device 47 that supplies power to thesecond detect device 45 is turned off while the display device 45a isdisplaying the message or producing the reminding sound, the controller45c performs substantially the same operation as described above todetect existence of an empty toner container 1 when the power to thepower supplying device 47 is turned on. Therefore, even when power tothe power supply device 47 is turned off while the display device 45a isdisplaying the message or producing the reminding sound and a firstoperator is replacing the toner container 1, because the message or thesound is turned off after the power to the power supply device 47 isturned on, if the set toner container 1 is not empty, it is preventedthat the newly set toner container 1 is erroneously replaced by anotheroperator. Further, even if power to the power supply device 47 is turnedoff while the display device 45a is displaying the message or producingthe reminding sound and such a message or sound is put off, the messageis displayed or the sound is produced again by the display device 45a,when the power to the power supply device 47 is turned on, if the settoner container 1 is empty. Therefore, the operator is reminded aboutreplacing the empty toner container 1.

FIG. 18 is a schematic drawing illustrating an exemplary construction ofthe toner discharging device 43. A cap 41b is taken off the opening 1aof a toner container 1 by a chuck 43a, which is moved in a direction Fin the drawing by a moving device (not shown). An inner holder 43d isrotated, while being held by a holder 43e, by rotation of a gear 43bprovided on an outer circumferential surface of the toner container 1,and a gear of a rotation drive device 43c. The gear 43b and the gear ofthe rotation drive device 43c are engaged with each other, and therebythe toner container 1 is rotated in synchronous with the inner holder43d. The toner contained in the toner container 1 is discharged throughthe opening 1a as the toner container 1 is rotated. When the toner inthe toner container 1 is exhausted, the chuck 43a is moved back in theopposite direction so as to close the opening 1a with the cap 41b.

FIG. 19 is a schematic drawing illustrating an exemplary construction ofthe toner delivery device 5. The toner delivery device 5 includes apowder pump generally called a Moineau pump described earlier. The tonerdelivery device 5 mixes the toner, which is exhausted from the tonercontainer 1 to the toner conveying path 410 and deposited in the mergedtoner conveyed path 41l, with air so as to deliver the mixture of tonerand air to the developing device 9 through the toner/air mixtureconveying path 8.

FIG. 20 is a schematic drawing illustrating an outer appearance of animage forming apparatus incorporating another embodiment of a tonersupplying device according to the present invention. In this embodiment,a cover open/close sensor 49 is provided at a part of the front surfaceof the toner supplying device 40 to detect if the cover 6 is opened orclosed, and the same cover open/close sensor 49 is configured to performthe function of the second detect device 45. Thus, in this embodiment,the cost of the second detect device 45 is made lower than in theprevious embodiment in which three sensors are used as the second detectdevice 45.

FIG. 21 is a schematic drawing illustrating an image forming apparatusincorporating a toner supplying device according to another embodimentof the present invention. In this embodiment, a first detect sensor 44dof a first detect device 44 is arranged at the merged toner conveyingpath 41l to detect the toner being conveyed to the merged tonerconveying path 41l. Thus, if the first detect sensor 44d detects notoner, it is determined that the operating toner container 1 is empty.Further, the first detect sensor 44d may be configured so as to alsofunction to detect if the toner deposited in the merged toner conveyingpath 411 exceeds a predetermined height, such that after the sensor 44ddetects no toner and the toner discharging device 43 for another tonercontainer 1 is activated to discharge toner, if the sensor 44d detectsno toner again, it is determined that the operating toner container 1 isempty. By configuring the first detect device 44 as above, the cost ofthe first detect device 44 is reduced.

FIG. 22 is a flowchart illustrating an exemplary operation of detectingexistence of an empty toner container 1 in the toner container insertionpart 2. The operation is performed by the controller 45c.

If the first detect device 44 for the operating toner container 1 doesnot detect toner in step S11, another toner container 1 is operated bythe toner discharging device 43 to discharge toner in step S12. Then,the display device 45a displays in step S13 the message reminding anoperator to replace the toner container 1 for which no toner is detectedby the first detect device 44. The second detect sensor 45b for the usedtoner container 1 then detects existence of the container 1 or the coveropen/close sensor 49 detects if the cover 6 is opened in step S14. Ifthe second detect sensor 45b detects existence of the toner container 1or the cover open/close sensor 49 detects that the cover 6 is not openedin step S14, then the display device 45a continues to display thereminding message in step S13. If the second detect sensor 45b detectsnon-existence of the toner container 1 or the cover open/close sensor 49detects that the cover 6 is opened in step S14, then in step S15, thesecond detect sensor 45b detects existence of the toner container 1again or the cover open/close sensor 49 detects again if the cover 6 isopened. If the second detect sensor 45b detects non-existence of thetoner container 1 again or the cover open/close sensor 49 detects thatthe cover 6 is opened, then it is determined that the used tonercontainer 1 is not yet replaced and the display device 45a continues todisplay the reminding message in step S13. If the second detect sensor45b detects the existence of the toner container 1 or the coveropen/close sensor 49 detects that the cover 6 is closed in step S15,then in step S16, it is determined that the used toner container 1 isreplaced. Then, the toner discharging device 43 for the newly set tonercontainer 1 is operated to discharge toner and is stopped after apredetermined period of time long enough for the first detect device 44to detect the toner being discharged from the newly set tonercontainer 1. If the first detect device 44 then detects no toner in stepS17, it is determined that the newly set toner container 1 is empty andthe display device 45a displays the message reminding the operator toagain replace the newly set toner container 1.

FIG. 23 is a schematic drawing illustrating a toner supplying deviceaccording to another embodiment of the present invention. A toner bank50 as a toner supplying device is configured such that a plurality oftoner containers 1, each containing toner can be inserted into a tonercontainer insertion part 2 from a front side 50a of the toner bank 50. Atoner container 1 is inserted in a direction indicated by an arrow A inthe drawing into respective toner container insertion parts 2 throughrespective insertion inlets 2a1, 2a2 and 2a3 and is detachably held byrespective toner container holders 53.

When the toner container 1 held by the toner container holder 53 isrotated by a rotation drive device (not shown), toner (T) contained inthe container 1 is discharged from the toner container 1 through anopening 1a. The opening 1a is provided at an axial end of the container1 in the direction in which the container 1 is inserted into the tonercontainer insertion parts 2. The discharged toner is exhausted to atoner exhausting path 55 provided at a rear end side of the tonercontainer insertion parts 2. The toner exhausted to the toner exhaustingpath 55 from each toner container 1 is conveyed to a toner deposit part510 at the bottom of the toner exhausting path 55. The toner depositedin the toner deposit part 510 is then mixed with air by a toner deliverydevice 5 and is conveyed via a toner/air mixture conveying path 8 to adeveloping device of an image forming apparatus (not shown) in which thetoner supplying device 50 is attached.

A toner container detect device 54 is arranged for each of the tonercontainer insertion parts 2 so as to detect existence of the tonercontainer 1 inserted into each of the toner container insertion parts 2and held by the corresponding toner container holder 53.

A toner detect device 57 is arranged in the toner deposit part 510 todetect existence of toner in the toner deposit part 510. The tonerdetect device 57 includes, for example, a sensor 57a that detects if thedeposited toner in the toner deposit part 510 exceeds a predeterminedheight. A control device 511 determines, based upon the detect resultwith the toner detect device 57, if the deposited toner in the tonerdeposit part 510 is running low.

Covers 6 are provided so as to cover and uncover parts of a frontsurface 50a of the toner bank 50, in which the insertion inlets 2a1, 2a2and 2a3 are provided. Further, an LED display device as a display device58 is arranged at a part of the front surface of each cover 6 so as todisplay detect results. The detect results include detecting existenceof an empty toner container 1 in the toner container insertion parts 2based on the respective toner container detect devices 54 and existenceof toner in each of the toner containers 1 inserted in the tonercontainer insertion parts 2 based on the toner detect device 57.

FIGS. 24(a), 24(b) and 24(c) are diagrams respectively illustrating anexample of an indication displayed in a display plane 58a of the displaydevice 58. The displays indicate results of detecting existence of anempty toner container 1 in the toner container insertion parts 2 withthe respective toner container detect devices 54 and existence of tonerin each of the toner containers 1 inserted in the toner containerinsertion parts 2 with the toner detect device 57. FIG. 24(a)illustrates an example of indicating that the toner container 1 existsin the corresponding container insertion part 2 and toner exists in thetoner container 1. In this example, the display plane 58a is notlighted. FIG. 24(b) illustrates an example of indicating that the tonercontainer 1 exists in the corresponding toner container insertion part 2and toner in the toner container 1 inserted in the corresponding tonerinsertion part 2 is running low or run out. The display of theindication may be slowly intermittent when toner is running low andrapidly intermittent when toner is run out. FIG. 24(c) illustrates anexample of indicating that a toner container 1 does not exist in thecorresponding toner container insertion part 2. In this example, thedisplay plane 58a is lighted when displaying this indication.

FIG. 25 is a flowchart of an operation of displaying results in thedisplay plane 58a of the display device 58. The display resultsindicates results of detecting existence of an empty toner container 1in the toner container insertion parts 2 with the respective tonercontainer detect devices 54. The displayed results also indicateexistence of toner in each of the toner containers 1 inserted in thetoner container insertion parts 2 with the toner detect device 57. Instep S21, each toner container detect device 54 detects if the tonercontainer 1 is inserted in the corresponding toner container insertionpart 2. Step S22 then determines if all of the container insertion parts2 include the toner container 1. If any of the toner container insertionparts 2 does not include the toner container 1, the control device 511astops supplying toner to the developing device of the image formingapparatus 100 in step S23, and then in step S24, displays in thecorresponding display plane 58a the indication indicating that tonercontainer 1 does not exists. If a new toner container 1 is inserted intothe corresponding toner container insertion part 2 and is detected instep S21, and then if the step S22 determines that all of the containerinsertion parts 2 include the toner container 1, the control device 511acontinues to supply toner to the developing device in step S25.

FIG. 26 is a schematic drawing illustrating a sectional view of a mainpart of the toner supplying device 50. As illustrated in the drawing,when the toner container 1 is inserted in the toner container insertionpart 2 and is held by the toner container holder 53, a filler 54a of thetoner container detect device 54 contacts a sensor 54b. Therefore, theexistence of the toner container 1 is detected. The sensor 54b includesa photo-interrupter, a limiting switch and so forth.

When the toner container detect device 54 detects a toner container 1,the indication indicating that the toner container 1 exists is displayedin the display plane 58a. Further, a shutter plate 59a of a shutter 59is driven by a drive motor 59b to move in a direction indicated by anarrow J. This opens the communication between the toner containerinsertion part 2 and the toner conveying path 55, such that toner can beexhausted to the toner conveying path 55 from the opening 1a of thetoner container 1.

FIG. 27 is a schematic drawing illustrating a sectional view of the mainpart of the toner supplying device 50 when a toner container 1 is notinserted in the toner insertion part 2. When the toner container 1 isnot inserted in the toner container insertion part 2, the filler 54a ofthe toner container detect device 54 is rotated in a counterclockwisedirection, such that the filler 54a does not interfere with the sensor54b, and thereby it is detected that a toner container 1 does not exist.When the toner container detect device 54 detects a toner container 1does not exist, the indication indicating that toner container 1 doesnot exist is displayed in the display plane 58a, and the shutter plate59a of the shutter 59 is driven by the drive motor 59b to move in adirection indicated by an arrow Z. This closes the communication betweenthe toner container insertion part 2 and the toner conveying path 55,such that scattering of toner through the opening 2a is prevented.

FIG. 28 is a flowchart of an operation of displaying the indication thata toner container 1 does not exist in the corresponding toner containerinsertion part 2, when the shutter 59 to close the communication betweenthe toner container insertion part 2 and the toner conveying path 55 isprovided. In step S31, each toner container detect device 54 detects thetoner container 1 inserted in the corresponding toner containerinsertion part 2. Step S32 then determines if any of the containerinsertion parts 2 include the toner container 1. If any of the tonercontainer insertion parts 2 includes the toner container 1, toner supplyto the developing device 9 is continued in step S35. When none of thetoner container insertion parts 2 include the toner container 1, thecontrol device 511a stops supplying toner to the developing device 9 instep S33. Then step S34 displays in the display plane 58a of eachdisplay device 58 the indication indicating that no toner container 1exists. If a new toner container 1 is inserted into any of the tonercontainer insertion parts 2 and the corresponding toner container detectdevice 54 detects the newly inserted toner container 1 in step S31, andthen if step S32 determines that the toner container insertion parts 2include the toner container 1, the control device 511a starts to supplytoner to the developing device 9 in step S35. Thus, another tonercontainer 1 can be inserted in another toner container insertion part 2.That is, a toner container 1 can be replaced while toner is beingsupplied to the developing device 9 in this embodiment.

FIG. 29 is a schematic drawing illustrating an example of an outerappearance of an image forming apparatus, including the toner bank 50 asa toner supplying device, according to the present invention. FIG. 30 isa sectional drawing illustrating the construction of this image formingapparatus.

As illustrated in FIG. 29, an image forming apparatus 100 includes thetoner bank 50 as the toner supplying device at a lower right part of theimage forming apparatus 100. The toner bank 50 includes, as describedabove, the display plane 58a for each toner container 1 held by thetoner container holder 53. The display plane 58a displays theindications to indicate the results of detecting with the tonercontainer detect device 54 existence of an empty toner container 1 inthe corresponding container insertion part 2, and the result ofdetecting with the toner detect device 57 existence of toner in thetoner container 1. In addition, the image forming apparatus 100 isprovided with a toner supply display device 105 having a toner supplydisplay plane 105a arranged in an operational panel 100c of the imageforming apparatus 100.

In FIG. 30, when power of a main motor (not shown) is turned on and atoner container 1 held by the toner container holder 53 starts to berotated by a rotation drive device 53a, toner (T) contained in the tonercontainer 1 is exhausted through an opening 1a into a toner exhaustingpath 55. The opening 1a is provided at an axial end of the container 1.The toner exhausted to the toner exhausting path 55 from each tonercontainer 1 is conveyed to a toner deposit part 510 at the bottom of thetoner exhausting path 55. The toner deposited in the toner deposit part510 is mixed with air by a toner delivery device 5 and is then conveyedto a developing device 9 of the image forming apparatus 100.

When a sensor 57a of the toner detect device 57 provided at a bottompart of the toner deposit part 510 detects that the toner at the tonerdeposit part 510 is below a predetermined height, the operating tonercontainer 1 is rotated to discharge toner through the opening 1a under acontrol of a control device 511a according to a detect signal from thesensor 57a. When the sensor 57a detects that the toner at the tonerdeposit part 510 is above the predetermined height, the toner container1 is stopped from being rotated to discharge toner, and both the displayplane 58a and the toner supply display plane device 105a of the tonersupply display device 105 (FIG. 29) display an indication indicatingthat a toner container 1 exists and toner exists in the toner container1.

When the sensor 57a detects that the toner in the deposit part 510 isbelow the predetermined height a predetermined number of times or for apredetermined period of time, the control device 511a determines thatthe toner contained in the operating toner container 1 is running low.Then, the control device 511a controls the rotation drive device 53a foranother toner container 1, for which the display plane 58a and the tonersupply display plane 105a are displaying the indication to indicate thata toner container 1 exists and toner exist in the container 1, to bedriven, such that the another toner container 1 is started to be rotatedby the rotation drive device 53a to discharge toner therefrom to thetoner conveying path 55 so as to be deposited in the toner deposit part510.

When a predetermined period of time elapses after the toner detectdevice 57 detects that the toner in the operating toner container 1 isrunning low, a cap 53g of the operating toner container 1 closes theopening 1a of the toner container 1. After the opening 1a of the tonercontainer 1 is closed by the cap 53g, both the display plane 58a and thetoner supply display plane 105a of the toner supply display device 105intermittently display the indication indicating that a toner container1 exists and the toner in the container 1 is running low or empty.Alternatively, the display of the indication may be slowly intermittentwhen the toner is running low and rapidly intermittent when the tonerhas run out. Thus, the remaining amount of toner in the toner bank 50 iseasily recognized via the above-described indications by an operator.Therefore, the operator is reminded of replacing the used tonercontainer 1, and consequently the intermittent supply of toner to thedeveloping device 9 is prevented. In addition, because the opening 1a ofthe used toner container 1 is closed with the cap 53g, scattering oftoner is prevented when the used toner container 1 is removed from thetoner supplying device 50.

FIGS. 31(a), 31(b), 31(c) and 31(d) are diagrams respectivelyillustrating another example of an indication of the display plane 58aof the display device 58 and the toner supply display plane 105a of thetoner supply display device 105. This displays are for indicating theresults of detecting existence of an empty toner container 1 in each ofthe toner container insertion parts 2 with the corresponding tonercontainer detect device 54 and existence of toner in each of the tonercontainers 1 inserted in each toner container insertion part 2 with thetoner detect device 57. FIG. 31(a) illustrates an indication for a statewhere a toner container 1 exists and toner exists in the container 1,FIG. 31(b) for a state where a toner container 1 exists and the toner isrunning low, FIG. 31(c) for a state where a toner container 1 exists andthe toner has run out, and FIG. 31(d) for a state where no tonercontainer 1 exists. With these indications, recognition of the remainingamount of the toner in the toner bank 50 is further facilitated.

FIG. 32 is a schematic drawing illustrating an exemplary construction ofthe toner delivery device 5 used in the toner supplying device 50. Thetoner delivery device 5 includes a powder pump generally called aMoineau pump described earlier. The toner delivery device 5 mixes thetoner, which is exhausted from the toner container 1 to the tonerconveying path 55 and deposited in the toner deposit part 510, with airso as to deliver the mixture of toner and air to the developing device 9through the toner/air mixture conveying path 8.

FIG. 33 is a schematic drawing illustrating the main portion of thedeveloping device 9 of the image forming apparatus 100 of FIG. 30 and isfor explaining control of toner supply from the toner bank 50 to thedeveloping device 9 with the control device 511 and a sensor 57bprovided to the toner supplying section 9b of the developing device 9.In FIG. 33, if the sensor 57b does not detect toner, that is, when theheight of the accumulated toner in the toner supplying section 9b of thedeveloping device 9 is lower than a predetermined level, the abovepowder pump unit 5 is driven to supply toner from the toner bank 50 tothe toner supplying section 9b of the developing device 9. When theheight of the accumulated toner in the toner supplying section 9breaches the predetermined level, the toner is detected by the sensor 57band the supply of toner to the toner supplying section 9b from the tonerbank 50 is stopped. With these controls, the toner supplying section 9balways contains a certain amount of toner, so that a stable developingprocess is assured. Additionally, if the sensor 57b does not detecttoner a predetermined number of times (i.e., at periodic orpredetermined intervals) or for a predetermined period of time, it isdetermined that the toner contained in the toner container 1 is almostexhausted. Then, toner contained in another toner container 1, for whichthe display plane 58a displays the indication that a toner container 1exists and toner exists in the container 1, starts to be operated by arotation drive device (not shown in FIG. 33) to exhaust the toner to thetoner conveying path 55, so as to be deposited in the toner deposit part510.

FIG. 34 is a flowchart illustrating an exemplary operation of detectingexistence of an empty toner container 1 in each of the toner containerinsertion parts 2 with the toner container detect device 54 andexistence of toner in the toner container 1 inserted in each tonercontainer insertion part 2 with the toner detect device 57, anddisplaying the detect result in the display plane 58a.

In step S41, the controller 511a or 511b of the controller 511determines if the main motor of the image forming apparatus 100 is on bydetecting existence of toner in the toner container 1 with the sensor57a or 57b of the toner detect device 57. If the main motor is on, stepS42 determines if a toner container 1 is inserted in each of the tonercontainer insertion parts 2 with the toner container detect device 54.If the toner container 1 is not inserted in each of the toner containerinsertion parts 2, step S43 displays in the corresponding display plane58a of the display device 58 the message indicating that a tonercontainer 1 does not exist. If the toner container 1 is inserted in anyof the toner container insertion parts 2, step S44 detects existence ofthe toner with the toner detect device 57. If the toner detect device 57detects the toner deposited in the toner deposit part 510 (i.e. thedeposited toner exceeds a predetermined height), step S45 turns off therotation drive device 53a for the operating toner container 1 for aperiod of time T1 to stop discharging the toner from the operating tonercontainer 1. Step S46 displays in the corresponding display plane 58athe message indicating that the toner container 1 exists and tonerexists in the toner container 1.

If the toner detect device 57 detects no toner (i.e., the depositedtoner does not exceed the predetermined height) in step S44, step S47turns on the rotation drive device 53a for the operating toner container1 for a period of time T2, and step S48 detects existence of toner withthe toner detect device 57. If the toner detect device 57 detects thetoner deposited in the toner deposit part 510 (i.e., the deposited tonerexceeds a predetermined height), step S49 turns off the rotation drivedevice 53a for a period of time T3 to stop discharging the toner fromthe operating toner container 1. Step S46 displays in the display plane58a the message indicating that the toner container 1 exists and tonerexists in the operating toner container 1.

If the toner detect device 57 detects no toner (i.e., the depositedtoner does not exceed the predetermined height) in step S48, step S50turns on the rotation drive device 53a for the operating toner container1 for a period of time T4, and step S51 detects existence of toner withthe toner detect device 57. If the toner detect device 57 detects thetoner deposited in the toner deposit part 510 (i.e., the deposited tonerexceeds the predetermined height), step S52 turns off the rotation drivedevice 53a for the operating toner container 1 for a period of time T5to stop discharging the toner from the toner container 1. Step S53displays in the display plane 58a the message indicating that the tonercontainer 1 exists and the toner in the operating toner container 1 isrunning out.

If the toner detect device 57 detects no toner (i.e., the depositedtoner does not exceed the predetermined height) in step S51, step S54determines that the operating toner container 1 is empty. Then, theopening 1a of another toner container 1 inserted in another tonercontainer insertion part 2 is opened by taking off the cap 53g of theanother toner container 1 and the stoppage of the drive of the rotationdrive 53a for the another toner container 1 is released. Step S55 thenturns on the rotation drive device 53a for the another toner container 1for a period of time T6. Step S56 closes the opening 1a of the usedtoner container 1 with the cap 53g and stops the drive of the rotationdrive device 53a for the used toner container 1. Step S57 then displaysin the display plane 58a for the used toner container 1 the messageindicating that the toner container 1 exists and the container 1 isempty.

FIG. 35 is a schematic sectional drawing illustrating an example of atoner supplying device according to another embodiment of the presentinvention, and FIG. 36 is a schematic drawing illustrating an imageforming apparatus incorporating the same toner supplying device.

A toner supplying device 60 is configured such that a toner container 1can be inserted through an insertion inlet 2a located at a front surface60a of the toner supplying device 60, so as to be attached to a tonercontainer insertion part 2 by manipulating an operation lever 68. Anarrow A1 indicates a direction to insert the toner container 1 into thetoner container insertion part 2 to be attached to the toner supplyingdevice 60, and an arrow A2 indicates a direction to detach the tonercontainer 1 from the toner supplying device 60.

An open/close device 63 that opens and closes an opening 1a of the tonercontainer 1 is provided at a position to face a cap 61b of the container1, with which the opening 1a of the container 1 is closed. Theopen/close device 63 puts the cap 61b on and off the opening 1a of thecontainer 1 so as to open and close the opening 1a by moving a movingmember 63a of the open/close device 63 in the directions indicated bythe arrows A1 and A2 in FIG. 35.

Toner (T) contained in the toner container 1 is discharged from thecontainer 1 to a toner exhaust path 610 when the toner container 1 isrotated by a rotation drive of a discharging device 69 after the cap 61bis detached from the opening 1a by the open/close device 63. Theexhausted toner is then conveyed to a toner supplying section 9b of adeveloping device 9 of the image forming apparatus 100 (illustrated inFIG. 36) via the toner conveying path 610.

A drive device 64 of the open/close device 63 is configured so as toapply to the moving member 63a of the open/close device 63 a drivingforce to move the cap 61b of the toner container 1 in the directions toopen and close the opening 1a of the container 1. That is, in thedirections indicated by the arrows A1 and A2 in FIG. 35. The drivedevice 64 is further configured so as to prevent the moving member 63afrom being moved when the drive device 64 does not apply the drivingforce to the moving member 63a in the directions indicated by the arrowsA1 and A2.

FIG. 37 is a schematic sectional drawing illustrating an example of atoner supplying device according to still another embodiment of thepresent invention, and FIG. 38 is a schematic drawing illustrating animage forming apparatus incorporating the same toner supplying device.

A toner supplying device 61 is configured such that two pieces of tonercontainers 1 can be inserted through a pair of insertion inlets 2alocated at a front surface 61a of the toner supplying device 61, so asto be attached to a toner insertion part 2 by manipulating an operationlever 68 provided for each insertion inlet 2a. An arrow A1 indicates adirection to insert the toner container 1 to be attached to the tonersupplying device 61, and an arrow A2 indicates a direction to detach thetoner container 1 from the toner supplying device 61.

Toner (T) discharged from each of the toner containers 1 is merged witheach other in the toner exhaust path 610 and then exhausted from thetoner exhaust path 610 to a toner conveying path 614 by a rotationmovement of a toner conveying screw 612 of a drive device 611. The toneris then conveyed, as illustrated in FIG. 38, by a toner delivery device613 including a powder diaphragm pump, to a toner supplying section 9bof a developing device 9 of the image forming apparatus 100 via thetoner conveying path 614. The toner supplying section 9b includes afilter 9b1 for passing air, such that air, which is mixed with toner, isexhausted.

FIGS. 39 and 40 are sectional drawings illustrating a structure of thetoner container insertion part 2 and the open/close device 63. Asillustrated in FIG. 39, in the toner container insertion part 2, thereis provided a rotatably-supported inner holder 62c in a holder 62b. Theinner holder 62c is rotated by a gear drive (not shown) via a drivinggear 62d. The toner container 1 has recess and projecting portions (notshown) so that it can rotate synchronously with this inner holder 62c.In the inner holder 62c, as shown in FIG. 39, a seal 62e is arranged soas to prevent toner from being scattered from a gap between the tonercontainer 1 and a supporting section of the inner holder 62c. In theholder 62b, a slider 63d and a chuck 63e are supported so as torespectively slide freely. The slider 63d is pressed by a spring 63f ina direction that urges the cap 61b toward the toner container 1. Whenthe chuck 63e is shifted in a direction indicated by an arrow B, asshown in FIG. 39, from this state, a grab portion 61b1 of the cap 61b isheld by a click 63e1 of the chuck 63e, and then the cap 61b is drawn outof the toner container 1, whereby the opening 1a is opened.

FIG. 40 illustrates a state of the open/close device 63 when the cap 61bis taken off the opening 1a of the toner container 1. In FIG. 40, whenthe driving gear 62d is rotated by a gear 69a of the rotation drivedevice 69 in this state, the inner holder 62c rotates and the tonercontainer 1 rotates synchronously with this rotation, whereby toner (T)in the toner container 1 is discharged from the opening 1a. If the toner(T) remaining in the toner container 1 becomes less than a predeterminedamount, as determined by the toner detect device (not shown) after apredetermined period of time long enough for using the remaining tonerof the toner container 1, the opening 1a of the toner container 1 isclosed by the cap 61b by shifting the chuck 63e with the drive device 64in a direction indicated by the arrow C in FIG. 40.

FIG. 41 is a schematic drawing illustrating the structure of the drivedevice 64. As illustrated in FIG. 41, the drive device 64 includes aworm wheel 64a, a worm 64b, a rotation drive unit 64c, a pinion 64d, anda rack 64e provided to the moving member 63a. The drive device 64 isconfigured so as to move the moving member 63a in the directionsindicated by arrows K and L by a rotation movement of the pinion 64d inclockwise and counterclockwise directions, respectively, with therotation drive device 64c. Because the drive device 64 is configured asabove so as to prevent the moving member 63a from being moved when thedrive device 64 does not apply the driving force to the moving member63a in the directions indicated by the arrows K and L, even when the cap61b is kept being removed from the opening 1a or the cap 61b is keptbeing placed in the opening 1a to close the opening 1a for a long time,the rotation drive device 64c does not need to keep being activated, andthereby power consumption is saved.

FIGS. 42(a) and 42(b) are schematic drawings illustrating anotherexample of the open/close device 63. The open/close device 63 includes adetect device 65 that detects a position 63c of a light transmittingpart 63a1 of the moving member 63a, at which the opening 1a of the tonercontainer 1 is closed with the cap 61b, when the moving member 63a ismoved in the direction indicated by an arrow L as illustrated in FIG.42(a), or a position 63b of another light transmitting part 63a2 of themoving member 63a, at which the cap 61b is removed from the opening 1ato open the opening 1a, when the moving member 63a is moved in adirection indicated by an arrow K as illustrated in FIG. 42(b). In thisexample, the moving member 63a is made of material which does nottransmit light. When each position is detected by the detect device 65,the drive device 64 stops the rotation movement with the rotation drivedevice 64c to stop the movement of the moving member 63a. Therefore, theworm wheel 64a and worm 64b are prevented from abrading each other atthe engaged part. Even when the output power of a motor of the rotationdrive device 64c is made small and an angle of the worm 64b relative toa moving direction of the worm 64b is small, such as for example, aboutthree degrees, the worm wheel 64a and the worm 64b are prevented fromabrading each other.

FIG. 43 is a schematic drawing illustrating still another example of theopen/close device 63. The open/close device 63 includes a control device63g that stores information of a number of steps to drive a steppingmotor 64c1 of the rotation drive device 64c to move the moving member63a to the position 63b at which the opening 1a of the toner container 1is closed with the cap 61b, when the moving member 63a is moved in thedirection indicated by an arrow L, or to the position 63c at which theopening 1a is closed with the cap 61b, when the moving member 63a ismoved in the direction indicated by an arrow K. Therefore, the wormwheel 64a and the worm 64b are prevented from abrading each other at theengaged parts. Even when the output power of the motor 64c1 is small andan angle of the worm 64b relative to a moving direction of the worm 64bis small, such as for example, about three degrees, the worm wheel 64aand the worm 64b are prevented from abrading each other at the engagedparts, and thereby the opening 1a is securely closed and opened with thecap 61b.

FIG. 44 is a schematic drawing illustrating still another example of theopen/close device 63. The open/close device 63 includes a shockabsorbing member 66, such as for example, a spring, at the positions 63band 63c, respectively. Therefore, even when the motor for the rotationdrive device 64c is turned off when the moving member 63a is moved tothe position 63b or 63c, the worm wheel 64a and the worm 64b areprevented from abrading each other at the engaged parts, and thereby theopening 1a is securely closed and opened with the cap 61b.

FIG. 45 is a schematic drawing illustrating an example of a constructionof the operation lever 68. In FIG. 45, the operation lever 68 releasesengagement of a stopper 62f and an engaging protrusion 61g of the tonercontainer 1. An elongated hole 68b is opened at the lever 68 and thelever 68 is arranged so as to slide relative to a fixing wall member 68dby fixing a screw 68c to the fixing wall member 68d through the hole68b. When the opening 1a of the toner container 1 is closed with the cap61b, and if the operation lever 68 is pushed in a direction indicated byan arrow E, a roller 68e, which is freely rotatable and held at aposition apart from the stopper 62f by a predetermined distance, slidesalong a slanted surface of the stopper 62f, and thereby the stopper 62fis moved downward as illustrated by a dotted line in FIG. 45. Thus, theengagement of the stopper 62f and the engaging protrusion 61g isreleased, such that the toner container 1 held by the holder 62b can beremoved from the holder 62b.

When the cap 61b is removed from the opening 1a of the toner container 1and the opening 1a is opened, even when the operating lever 68 is pushedto the direction indicated by the arrow E, the engagement of the stopper62f and the engaging protrusion 61g is prevented from being released bya toner container removal prevention device 67, that includes aconnecting rod 67a mechanically connecting to the moving member 63a anda roller 67a1 provided at a tip end of the connecting rod 67a. That is,the toner container 1 is prevented from being removed from the holder62b when the opening 1a of the toner container 1 is not closed with thecap 61b.

When the toner bank 70 is inserted into the apparatus 100, the tonerbank 70 is positioned in a position to be attached to the main body 0 ofthe apparatus 100 by a positioning member (not shown) and is fixed tothe main body 0 of the apparatus 100 by fixing screws 712 as a fixingmember. The screws 712 are removed when detaching the toner bank 70 fromthe main body 0 of the apparatus 100. Because the toner bank 70 can bedetached from the main body 0 of the apparatus 100, as described above,the toner bank 70 can be assembled separately from the main body 0 ofthe apparatus 100, such that assembling of the main body 0 can befacilitated. Further, because the toner bank 70 is fixed when attachedto the main body 0, the toner bank 70 is prevented from beingunnecessarily detached from the main body 0. Therefore, unnecessarystoppage of the image forming operation due to unnecessary detachment ofthe toner bank 70 from the apparatus 100 is prevented.

The opening 0a1 may alternatively be provided facing a side of theapparatus 100, for example, facing the side of the apparatus 100 where acopysheet exit tray 77 of the image forming apparatus 100 is located,such that the toner bank 70 (indicated by a dotted line) can be insertedinto or removed from the main body 0 in a direction indicated by anarrow M in FIG. 48. By thus arranging the opening 0a1, the open spacebelow the copysheet exit tray 77 is effectively utilized.

A guide member 78 is provided, as illustrated in FIG. 48, at the side ofthe toner bank 70 so as to guide the toner bank 70 in a direction to beinserted into or removed from the main body 0. Thus, the toner bank 70can be easily attached to and detached from the main body 0. Inaddition, a handhold 711 is provided, for example, at a front surface ofthe toner bank 70 so as to facilitate the operation of inserting andremoving the toner bank 70 to and from the main body 0.

FIG. 49 is a schematic drawing illustrating an example of an imageforming apparatus including a toner supplying device, according toanother embodiment of the present invention. In FIG. 49, a guide member79 of a toner supplying device holder 72 includes a pair of guide rails79a provided at an outer circumferential surface 0a located below acopysheet exit tray 77 and a pair of guide rails 79b provided at anupper surface of a toner bank 70. When attaching and detaching the tonerbank 70 to and from a main body 0 of the image forming apparatus 100,the guide rails 79a and 79b engage with each other such that the tonerbank 70 is guided in a direction indicated by an arrow K so as to beinserted into or removed from the main body 0. When attaching the tonerbank 70 to the main body 0, the toner bank 70 is positioned in aposition to be attached to the main body 0 by four positioning members710 provided at the outer circumferential surface 0a below the copysheetexit tray 77. The toner bank 70 is then fixed by fixing screws 712 tothe main body 0. When detaching the toner bank 70 from the main body 0,the screws 712 are removed. The toner bank 70 is provided with ahandhold 711 at both end sides of a front surface of the toner bank 70so as to facilitate an operation of inserting and removing the tonerbank 70 into and from the main body 0.

Obviously, numerous additional modifications and variations of thepresent inventions are possible in light of the above teachings. Inparticular, features described for certain embodiments may be employedin a logical manner to other embodiments described herein. It istherefore to be understood that within the scope of the appended claims,the present invention may be practiced otherwise than as specificallydescribed herein.

This document is based on Japanese patent applications No. 10-027745filed in the Japanese Patent Office on Jan. 26, 1998, No. 10-067913filed on Mar. 3, 1998, No. 10-073605 filed on Mar. 6, 1998, No.10-092736 filed on Mar. 20, 1998, and No. 10-120001 filed on Apr. 14,1998, each of which the entire contents are incorporated by reference.

What is claimed as new and is desired to be secured by Letters Patent ofthe United States is:
 1. A toner supplying device for supplying tonercontained in a toner container to a developing device of an imageforming apparatus, the toner supplying device comprising:a tonercontainer insertion part configured to receive an inserted tonercontainer from a front side of the toner supplying device; a tonercontainer holder that detachably holds the toner container inserted intothe toner container insertion part; a toner exhaust path to which toner,discharged from the toner container held by the toner container holder,is exhausted; a toner delivery device that delivers the toner exhaustedto the toner exhaust path to the developing device of the image formingapparatus by mixing the toner with air; and a covering device thatcovers and uncovers the toner container insertion part, wherein thecovering device includes a regulating device that prevents movement ofthe covering device of the toner container insertion part when toner isbeing discharged from the toner container held by the toner containerholder in the toner container insertion part.
 2. The toner supplyingdevice of claim 1, wherein the toner container insertion part includes aplurality of toner container insertion parts configured to receive acorresponding plurality of inserted toner containers from the front sideof the toner supplying device.
 3. The toner supplying device of claim 2,wherein the covering device includes a plurality of covering devicesthat cover and uncover the plurality of toner container insertion parts.4. The toner supplying device of claim 3, wherein each of the pluralityof covering devices include a regulating device that prevents movementof a covering device of a corresponding toner container insertion partwhen toner is being discharged from the toner container held by thetoner container holder in the corresponding toner container insertionpart.
 5. The toner supplying device of claim 4, wherein each regulatingdevice releases a regulating movement of the covering device of thecorresponding toner insertion part when toner is not being dischargedfrom the toner container held by the toner container holder in thecorresponding toner container insertion part.
 6. An image formingapparatus, comprising:a developing device; and a toner supplying devicefor supplying toner contained in a toner container to the developingdevice, the toner supplying device having: a toner container insertionpart configured to receive an inserted toner container from a front sideof the toner supplying device; a toner container holder that detachablyholds the toner container inserted into the toner container insertionpart; a toner exhaust path to which toner, discharged from the tonercontainer held by the toner container holder, is exhausted; a tonerdelivery device that delivers the toner exhausted to the toner exhaustpath to the developing device by mixing the toner with air; and acovering device that covers and uncovers the toner container insertionpart, wherein the covering device includes a regulating device thatprevents movement of the covering device of the toner containerinsertion part when toner is being discharged from the toner containerheld by the toner container holder in the toner container insertionpart.
 7. The image forming apparatus of claim 6, wherein the tonercontainer insertion part includes a plurality of toner containerinsertion parts configured to receive a corresponding plurality ofinserted toner containers from the front side of the toner supplyingdevice.
 8. The image forming apparatus of claim 7, wherein the coveringdevice includes a plurality of covering devices that cover and uncoverthe plurality of toner container insertion parts.
 9. The image formingapparatus of claim 8, wherein each of the plurality of covering devicesinclude a regulating device that prevents movement of a covering deviceof a corresponding toner insertion part when toner is being dischargedfrom the toner container held by the toner container holder in thecorresponding toner container insertion part.
 10. The image formingapparatus of claim 9, wherein each regulating device releases aregulating movement of the covering device of the corresponding tonerinsertion part when toner is not being discharged from the tonercontainer held by the toner container holder in the corresponding tonercontainer insertion part.
 11. The image forming apparatus of claim 6,further comprising a front cover that opens and closes, andwherein animage forming operation is stopped when the front cover is opened, andthe toner supplying device is arranged so as to be free from movement ofthe front cover to open and close.
 12. An image forming apparatus,comprising:a developing device; a toner supplying device for supplyingtoner contained in a toner container to the developing device, the tonersupplying device having: a toner container insertion part configured toreceive an inserted toner container from a front side of the tonersupplying device; a toner container holder that detachably holds thetoner container inserted into the toner container insertion part; atoner exhaust path to which toner, discharged from the toner containerheld by the toner container holder, is exhausted; and a toner deliverydevice that delivers the toner exhausted to the toner exhaust path tothe developing device by mixing the toner with air; and a front coverthat opens and closes, and wherein an image forming operation is stoppedwhen the front cover is opened, and the toner supplying device isarranged so as to be free from movement of the front cover to open andclose.
 13. The image forming apparatus of claim 12, wherein the tonercontainer insertion part includes a plurality of toner containerinsertion parts configured to receive a corresponding plurality ofinserted toner containers from the front side of the toner supplyingdevice.
 14. The image forming apparatus of claim 13, wherein the tonersupplying device further includes a plurality of covering devices thatcover and uncover the plurality of toner container insertion parts. 15.The image forming apparatus of claim 14, wherein each of the pluralityof covering devices include a regulating device that regulates movementof a covering device of a corresponding toner insertion part when toneris being discharged from the toner container held by the toner containerholder in the corresponding toner container insertion part.
 16. Theimage forming apparatus of claim 15, wherein each regulating devicereleases a regulating movement of the covering device of thecorresponding toner insertion part when toner is not being dischargedfrom the toner container held by the toner container holder in thecorresponding toner container insertion part.
 17. The image formingapparatus of claim 12, wherein the toner supplying device furtherincludes a covering device that covers and uncovers the toner containerinsertion part.
 18. The image forming apparatus of claim 17, wherein thecovering device includes a regulating device that regulates movement ofthe covering device of the toner container insertion part when toner isbeing discharged from the toner container held by the toner containerholder in the toner container insertion part.